Regal V6-173 2.8L (1988)
Transmission Position Switch/Sensor: Description and Operation
PURPOSE
The Park/Neutral (P/N) switch indicates to the Electronic Control Module (ECM) when the transmission is in Park, Neutral or Drive. This
information is used for the Torque Converter Clutch (TCC), Exhaust Gas Recirculation (EGR) and the Idle Air Control (IAC) valve operation.
OPERATION
The park/neutral switch contacts are a part of the neutral start switch and are closed to ground in park or neutral, and open in the drive ranges. The
Electronic Control Module (ECM) supplies ignition voltage through a current limiting resistor to circuit 434 and senses a closed switch when the
voltage on circuit 434 drops to less than one volt.
CAUTION: Vehicle should NOT be driven with the park/neutral switch disconnected, as idle quality will be affected and a possible false Code 24
Vehicle speed Sensor (VSS).
Refer to Computers and Controls / System Diagnosis / Procedures / Diagnostic Charts / Code 24. See: Powertrain Management/Computers and
Control Systems/Testing and Inspection
